A cataract is a painless, cloudy area in the lens of the eye that blocks the passage of light to the retina. The retina is the nerve layer at the back of the eye. The nerve cells in the retina detect light entering the eye and send nerve signals to the brain about what the eye sees. Because cataracts block this light, they can cause vision problems.
Aging and exposure to sunlight can cause cataracts. Changes in your eyes are often a normal part of aging. But the changes do not always lead to cataracts.
Cataracts can also happen after an eye injury, as a result of eye disease, after you use certain medicines, or as a result of health problems such as diabetes.
Sometimes children are born with cataracts.
Cataracts can affect your vision.
The vision loss from a cataract often happens slowly and may never become severe. Sometimes cataracts do not cause any vision problems.
Your doctor can find out if you have cataracts by doing a physical examination and by asking questions about your symptoms and past health. You may need tests to make sure you have a cataract or to rule out other conditions that may be causing vision problems.
Surgery can remove cataracts. For most adults, surgery is only needed when vision loss caused by a cataract affects their quality of life.
There are a number of things you can do that may help you manage your vision problems. Many people get along very well with the help of eyeglasses, contacts, or other vision aids. Keep your eyeglasses or contact lens prescription up to date. Also make sure you have plenty of lighting in your home. You may be able to avoid or delay surgery.
Whether you need cataract surgery depends on how much of a problem the cataract causes for daily activities like driving and reading. Surgery is almost always by your choice (elective) and can be scheduled when it is convenient. For people who decide to have surgery, the surgery usually works very well.
Some people have to have surgery. Children are sometimes born with cataracts that need to be removed. Other people may get cataracts after an eye injury or as a result of eye disease or other health problems. Cataracts from these causes may also need to be removed.
There is no proven way to prevent cataracts. But there are some things you can do that may help slow cataract growth. Don't smoke. Wear a hat or sunglasses when you are in the sun. And avoid sun lamps and tanning booths. Eat healthy foods. And keep diabetes under control.
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A cataract occurs when the lens inside your eye becomes cloudy. Things linked to clouding include:
Not all cataracts impair vision or affect daily living. For those that do, common symptoms include:
Parents need to watch for signs of cataracts in infants and children.
Cataracts may stay small and you may not notice them. They often do not seriously affect vision. And many cataracts do not need to be removed.
Some cataracts grow larger or denser over time, causing severe vision changes.
As a cataract progresses, more of the lens becomes cloudy. When the entire lens is white, the cataract is called a "ripe" or "mature" cataract and causes severe vision problems. Delaying surgery until cataracts are ripe or mature is neither recommended nor needed.
Cataracts in children are rare but serious. If a cataract prevents light from entering a child's eye and stimulating the retina, the area of the brain used for sight does not develop properly. Usually the child won't see well with that eye (amblyopia), even if the cataract is later removed.
Things that increase your risk for cataracts include:
Some chronic diseases increase the risk for cataracts. Keeping these diseases under control may help lower your risk for cataracts:
Other things that may increase your risk include:
Call your doctor right away if you have:
Call your doctor to discuss your symptoms if you:
If you are an older adult, discuss with your doctor how often you need to have routine eye examinations.
If a doctor has not determined that you have cataracts but you have symptoms that concern you, see the topic Eye Problems, Non-Injury to find more information on what to do about your symptoms.
Watchful waiting is a wait-and-see approach. Watchful waiting is safe and appropriate in most cases of adult cataracts. If you notice signs that your baby or child may not be seeing well, see your doctor. Cataracts in children should be treated right away.
Speak with an ophthalmologist about surgery to remove cataracts. In most cases, you can decide if you want or need surgery based on whether vision problems caused by the cataract are interfering with your daily activities.
Your optometrist, family doctor, or general practitioner can evaluate vision problems that may be caused by a cataract. You may also be referred to an ophthalmologist.
While other doctors may be able to detect problems that may be caused by cataracts, only an ophthalmologist can treat cataracts.
Diagnosis of cataracts is based on a medical history and physical examination.
Often tests are used to:
For more information, see:
When you are deciding whether to have surgery, you may find it very helpful to evaluate the effect that vision loss from a cataract has on your life. Your doctor may ask you to complete a questionnaire regarding the effect of the cataract on your daily activities.
If you already have some vision loss that cannot be corrected by cataract surgery, your doctor may do a low-vision evaluation to help find ways for you to make the most of your remaining vision and to keep your quality of life.
During routine eye examinations, your eye doctor will look for early signs of vision problems, including cataracts.
Testing your child for cataracts may be needed if you think your child is having a vision problem.
Surgery to remove a cataract is the only way to get rid of a cataract. This surgery works well and helps people see better. But surgery is often not needed or can be delayed for months or years. Many people with cataracts get along very well with the help of eyeglasses, contacts, and other vision aids.
Whether surgery is needed for an adult with cataracts depends on the degree of vision loss and whether it affects quality of life and ability to function.
The choices for treating cataracts in children depend on how likely the cataracts are to interfere with the development of normal vision.
Sometimes a cataract needs to be removed because of another eye disease, such as diabetic retinopathy or macular degeneration. In some cases the cataract has to be removed so that the eye specialist can treat the retina, the nerve layer at the back of the eye.
Misconceptions about cataracts are common. More and more medical centres have been built specifically for cataract surgery. Marketing campaigns aimed at older adults may encourage some people to have surgery when they do not really need it. Because of fear of blindness or loss of independence, older adults may think they need to have surgery even when their cataracts do not affect their quality of life. In many cases, wearing eyeglasses or contacts and using other vision aids might be appropriate and just as effective without any of the risks of surgery.
Only you can decide whether a cataract is affecting your vision and your life enough to have surgery. If surgery is not going to improve your vision, you may decide that surgery is not for you.
There is no proven way to prevent cataracts. But certain lifestyle habits may help slow cataract development. These include:
For more information, see the topics:
If you have cataracts, these tips and vision aids may help you manage your vision problems and avoid or delay surgery:
Evidence shows that making certain lifestyle changes such as not smoking and protecting your eyes from sunlight may help slow the development of cataracts.
Your doctor will give you instructions about what to do after cataract surgery. Eye care for adults after cataract surgery includes using prescribed eyedrops, protecting your eye, and watching for signs of infection.
Contact your doctor promptly if you notice any signs of complications, such as:
It is normal to have blurred vision and some swelling after surgery. It takes time for the swelling to go down. Your eyeglass prescription may change after surgery.
A small number of adults and children with cataracts may benefit for a short time from eyedrops that widen (dilate) the pupil. These eyedrops increase the amount of light getting into the eye. They are sometimes used to help prevent vision loss in very young children who need to wait for surgery to be done.
There is currently no medicine that will cure cataracts.
Surgery for cataracts involves removing the clouded lens of the eye (the cataract). The lens can be replaced with an artificial lens called an intraocular lens implant (IOL). Or, if an IOL cannot be used for any reason, it will be left out and contact lenses or, in rare cases, eyeglasses can compensate for its absence. Most people will get an IOL during surgery.
Before surgery, ask your doctor about what types of IOLs can go in your eye. Or, if you will not be getting an IOL, find out why, and ask about the pros and cons of contact lenses or eyeglasses.
For most adults, surgery is only needed when vision loss caused by a cataract affects your quality of life. The goals of surgery in adults who have cataracts include:
The choices for treating cataracts in children depend on how likely the cataracts are to interfere with the development of normal vision. Surgery for cataracts in children may be needed.
For adults who have cataracts in both eyes, surgery is not normally done on both eyes at the same time. The first eye needs to heal. Then your doctor will determine how much eyesight has improved before surgery is done on the second eye.
If you have both glaucoma and cataracts, you may have surgery for both conditions at the same time. Depending on which condition caused the vision loss, vision may improve after surgery.
There are two main types of cataract surgery. They are both done in an outpatient centre. The decision about which one to use depends on what kind of cataract you have and how much experience the surgeon has with each type of surgery.
The most common problem after cataract surgery is clouding of the posterior lens capsule (called aftercataract) within 5 years after surgery. This clouding is usually not a serious problem. And it is easy to treat with a laser surgery (Nd:YAG laser posterior capsulotomy) if it occurs.
Just because you have a cataract doesn't mean you need to have it removed. Only you can decide whether cataracts are affecting your vision and your life enough for you to have surgery. Learn what to ask about cataract surgery before deciding whether to have the surgery.
For adults, cataract surgery is almost always elective and can be done at your convenience. The surgeon, or someone familiar with routine surgical practices, will usually be available for any follow-up examinations and treatment.
Surgery may be advisable if you want to continue to drive a car. If you live in a retirement home or assisted-living facility, you may decide to use vision aids and avoid surgery.
If you do not have another eye condition, such as glaucoma or problems with your retina, your chances of seeing better after cataract surgery are very good. But you may still need reading glasses or glasses for near vision.
Other Works Consulted
Awasthi N, et al. (2009). Posterior capsular opacification. Archives of Ophthalmology, 127(4): 555–562.
Harper RA, Shock JP (2011). Lens. In P Riordan-Eva, JP Whitcher, eds., Vaughan and Asbury's General Ophthalmology, 18th ed., pp. 174–182. New York: McGraw-Hill.
Long V, et al. (2007). Surgical interventions for bilateral congenital cataract. Cochrane Database of Systematic Reviews (1).
Mathew MC, et al. (2012). Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract. Cochrane Database of Systematic Reviews (6).
Wright KW (2008). Leukocoria: Cataracts, retinal tumors, and Coats disease. In Pediatric Ophthalmology for Primary Care, 3rd ed., pp. 285–310. Elk Grove Village, IL: American Academy of Pediatrics.
Current as ofJuly 17, 2018
Author: Healthwise StaffMedical Review: Kathleen Romito, MD - Family MedicineDonald Sproule, MDCM, CCFP - Family MedicineAdam Husney, MD - Family MedicineCarol L. Karp, MD - Ophthalmology
Current as of: July 17, 2018
Kathleen Romito, MD - Family Medicine & Donald Sproule, MDCM, CCFP - Family Medicine & Adam Husney, MD - Family Medicine & Carol L. Karp, MD - Ophthalmology
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